Effect of Shaft and Bearing Flexibility on Dynamic Behavior of Helical Gears: Modeling and Experimental Comparisons

Abstract

We propose a mathematical model for analyzing the effect of shaft and bearing flexibility on the dynamic behavior of helical gears. A primary feature of this study is that gear mesh stiffness is not just determined by the geometry of the gear pair but also by the center distance between the two gears. We present a six-degrees-of-freedom (DOF) model of helical gears to calculate the mesh forces from the deformations of teeth and the mesh stiffness of the corresponding spur gear pair. The pressure angle and contact ratio of the gear pair are treated as time-varying values and updated at each iteration during calculations. The predicted results show that if the deformations of the shafts and bearings are taken into consideration, the pressure angle and contact ratio will change significantly and the gear pair will exhibit larger vibration. We conducted experimental tests to validate the proposed model. The experimental data show good agreement with the predicted results.